RESUMEN
OBJECTIVE: To determine the anesthetic and surgical morbidity associated with postpartum tubal ligation after pregnancy complicated by pregnancy-induced hypertension. METHODS: Preoperative hemodynamic measurements, laboratory results, choice of anesthetic technique, intraoperative hemodynamic changes, and postoperative morbidity were compared in 53 women with pregnancy-induced hypertension (hypertensive group) and 53 controls who underwent postpartum tubal ligation between October 1992 and November 1995. We used a retrospective case-control design. RESULTS: Preoperative mean blood pressure (BP) measurements ( +/- standard deviation) were greater in hypertensive women than in controls (158 +/- 22/91 +/- 12 versus 126 +/- 13/71 +/- 10 mmHg; P < .001). Among women given spinal anesthetics for tubal ligation, the minimum intraoperative systolic BP was significantly lower in controls than in hypertensive women (P < .05). However, the maximum percentage decrease in systolic BP was greater in hypertensive women than in controls (33 +/- 14 versus 22 +/- 10%; P < .05). Only one patient in each group developed intraoperative hypertension. The percentage of patients discharged later than the first postoperative day was greater in hypertensive women than in controls (23 versus 8%; P < .05). CONCLUSION: The lack of profound hemodynamic responses during spinal or general anesthesia for postpartum tubal ligation supports the continued use of this procedure in selected women with pregnancy-induced hypertension.
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Hipertensión , Periodo Posparto , Preeclampsia , Complicaciones Cardiovasculares del Embarazo , Esterilización Tubaria , Femenino , Humanos , Embarazo , Complicaciones Cardiovasculares del Embarazo/fisiopatologíaRESUMEN
OBJECTIVE: To compare pregnancy rates after fallopian tubal and uterine transfer of cryopreserved embryos. DESIGN: Prospective randomized trial with assignment to treatment groups by a random number table. SETTING: University of Iowa Hospitals and Clinics, a tertiary care academic institution. PATIENTS: Forty patients with patent fallopian tubes and at least three cryopreserved embryos. INTERVENTIONS: Cryopreserved embryos were thawed and transferred to the fallopian tube by laparoscopy or to the uterus by a transcervical catheter. MAIN OUTCOME MEASURES: Clinical and ongoing pregnancy rates. RESULTS: Tubal transfer of cryopreserved embryos resulted in statistically higher clinical (68% versus 24%) and ongoing pregnancy rates (58% versus 19%) when compared with uterine transfer. CONCLUSIONS: Tubal transfer of cryopreserved embryos is highly effective and offers an improved pregnancy rate when compared with uterine transfer of embryos. This method of transfer should be considered in patients with patent fallopian tubes and at least three cryopreserved embryos.
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Criopreservación , Transferencia de Embrión/métodos , Trompas Uterinas , Útero , Adulto , Femenino , Hormona Folículo Estimulante/uso terapéutico , Humanos , Leuprolida/uso terapéutico , Embarazo , Resultado del Embarazo , Estudios Prospectivos , Resultado del TratamientoRESUMEN
BACKGROUND AND OBJECTIVES: The American College of Obstetricians & Gynecologists has opposed postpartum tubal ligation (PPTL) in patients whose pregnancies have been complicated by a medical condition, including hypertension. A prospective study was conducted to assess the appropriateness of spinal anesthesia for PPTL in patients with hypertensive disorders of pregnancy. METHODS: After institutional review board approval and written informed consent, women scheduled for PPTL were enrolled. The hypertensive group (n = 25) consisted of women whose pregnancies were complicated by gestational hypertension, preeclampsia, or chronic hypertension with superimposed preeclampsia. For each hypertensive patient, a matched control was designated by selecting the next consenting normotensive patient scheduled for PPTL. After an intravenous bolus of lactated ringers solution 500 mL, spinal anesthesia was induced with hyperbaric lidocaine. Hemodynamic measurements were recorded every 2 minutes for 20 minutes after spinal injection. Ephedrine IV was administered for systolic blood pressure < or =90 mm Hg. RESULTS: The mean preoperative mean blood pressure (MAP) was 107+/-17 mm Hg in the hypertensive group and 85+/-11 mm Hg in the controls, P<.0001. The hypertensive group sustained a more profound percentage decrease in MAP than did their control counterparts during spinal anesthesia (29%+/-12% v. 15%+/-8%, P<.0001). However, the lowest intraoperative MAP was similar in both groups. Thirty-five percent of hypertensive patients and 24% of the controls received ephedrine IV. CONCLUSIONS: PPTL during spinal anesthesia in patients whose pregnancies have been complicated by hypertension had results comparable with patients with uncomplicated pregnancies; however, further studies are needed to ascertain its safety.
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Anestesia Raquidea , Hipertensión/complicaciones , Periodo Posparto , Preeclampsia/complicaciones , Complicaciones Cardiovasculares del Embarazo , Esterilización Tubaria , Adulto , Análisis de Varianza , Anestésicos Locales/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Estudios de Casos y Controles , Efedrina/administración & dosificación , Efedrina/uso terapéutico , Femenino , Humanos , Inyecciones Intravenosas , Soluciones Isotónicas , Lidocaína/administración & dosificación , Monitoreo Intraoperatorio , Embarazo , Presión , Estudios Prospectivos , Lactato de Ringer , Seguridad , Vasoconstrictores/administración & dosificación , Vasoconstrictores/uso terapéuticoRESUMEN
Rhinocerebral mucormycosis is a fungal diseases that has a 50% mortality. Its occurrence has increased, possibly because of greater use of chemotherapeutic agents that mya compromise the immunologic defenses of the host or alter the normal flora. The earliest signs, ulceration and pain, may appear in the mouth. In the patient described in this report, the autopsy showed that mucormycosis had entered the brain cells.
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Encefalopatías/patología , Enfermedades de la Boca/patología , Mucormicosis/patología , Enfermedades Nasales/patología , Anfotericina B/uso terapéutico , Femenino , Humanos , Persona de Mediana Edad , Mucormicosis/tratamiento farmacológico , Necrosis/patología , Pronóstico , Úlcera/patologíaRESUMEN
The purpose of this study was to determine which of the two positions used by anesthesiologists to identify the epidural space is more comfortable for pregnant patients. We evaluated both the lateral decubitus position and the sitting position in 90 term parturients who were either not in labor or were in early labor (
RESUMEN
STUDY OBJECTIVES: To evaluate the success of epidural anesthesia for postpartum tubal ligation using epidural catheters placed during labor and to determine whether patient characteristics, timing of surgery, or technical factors (e.g., length of epidural catheter inserted into the epidural space) influenced the success of subsequent epidural anesthesia. DESIGN: Retrospective study. SETTING: University hospital labor and delivery suite. PATIENTS: 90 consecutive women scheduled for postpartum tubal ligation using epidural catheters placed during labor. INTERVENTIONS: Epidural catheters were reinjected with 1.5% to 2% lidocaine with epinephrine 5 micrograms/ml or 2% to 3% 2-chloroprocaine immediately before surgery. MEASUREMENTS AND MAIN RESULTS: 74% of the women received satisfactory intraoperative anesthesia using in situ epidural catheters. Reinjecting the catheter within 4 hours of delivery was associated with a greater frequency of successful epidural anesthesia for tubal ligation (95% vs. 67%; p = 0.029). There was no significant difference between the two groups in the length of catheter inserted into the epidural space. CONCLUSIONS: Although other factors may influence the timing of postpartum tubal ligation after delivery, the success of epidural anesthesia for tubal ligation using in situ epidural catheters is greater if surgery is performed shortly after delivery.
Asunto(s)
Anestesia Epidural , Periodo Posparto , Esterilización Tubaria/métodos , Adulto , Catéteres de Permanencia , Espacio Epidural , Femenino , Humanos , Trabajo de Parto , Embarazo , Estudios Retrospectivos , Esterilización Tubaria/instrumentación , Factores de TiempoRESUMEN
STUDY OBJECTIVE: To evaluate whether 360 ml of oral clear liquids consumed within 4 hours of elective surgery worsens gastric volume and acidity in patients given acid aspiration prophylaxis. DESIGN: Randomized, unblinded study. SETTING: Main operating room at a U.S. military hospital. PATIENTS: Eighty-three adult inpatients scheduled to receive general anesthesia for elective surgery. INTERVENTIONS: Nineteen patients (Group 1) were given 150 mg of oral ranitidine (two doses), 10 mg of metoclopramide, and 360 ml of apple juice 3 hours before the scheduled start of surgery. Thirty-four patients (Group 2) fasted before surgery but received acid aspiration prophylaxis identical to that given to Group 1. Twenty-three additional patients (Group 3) received no oral fluids or acid aspiration prophylaxis before surgery. MEASUREMENTS AND MAIN RESULTS: The residual gastric volume (RGV) and the pH of Group 1 patients were compared with measurements obtained in the two groups of patients who fasted. RGV measurements in Group 1 (14 +/- 3 ml) were similar to those in Group 2 (11 +/- 2 ml) and were significantly less than (p less than 0.05) those in Group 3 (26 +/- 4 ml). Gastric pH was significantly higher (p less than 0.001) in Group 1 (5.16 +/- 0.69) and Group 2 (5.78 +/- 0.43) than in Group 3 (1.97 +/- 0.27). CONCLUSIONS: Three hundred and sixty ml of apple juice consumed within 4 hours of elective surgery by patients given ranitidine and metoclopramide did not worsen gastric volume and acidity.
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Bebidas/efectos adversos , Frutas , Metoclopramida/uso terapéutico , Neumonía por Aspiración/prevención & control , Ranitidina/uso terapéutico , Administración Oral , Adulto , Femenino , Ácido Gástrico/metabolismo , Humanos , Masculino , Metoclopramida/administración & dosificación , Persona de Mediana Edad , Ranitidina/administración & dosificación , Procedimientos Quirúrgicos OperativosRESUMEN
This survey of 325 Oklahoma City Firefighters examined their perceptions of the effect of the bombing, their recovery and their sources of support. Other variables that were considered in this analysis included age, usefulness of the Critical Incidence Stress Management (CISM) procedures, and attitude, an aggregate variable that accounted for job satisfaction. Of particular importance in this analysis was the finding that support from "faith" was a primary predictor of positive outcome and positive attitude over the one-year period. However, the effect of the variable differed for older and younger firefighters. That is, there was a greater proportion of younger firefighters among those reporting greater support from faith. These data suggest that, at least in this geographic area, chaplains, and other spiritual leaders may play a particularly important role in the aftermath of such a disaster.
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Explosiones , Incendios , Salud Laboral , Adulto , Factores de Edad , Humanos , Persona de Mediana Edad , Oklahoma , Apoyo Social , ViolenciaRESUMEN
Epidural analgesia is a commonly employed technique of providing pain relief during labor. The number of parturients given intrapartum epidural analgesia is reported to be over 50 percent at many institutions in the United States. The procedure has few contraindications, the primary ones being patient refusal, maternal hemorrhage and coagulopathy. Induction of epidural analgesia in early labor remains controversial. However, many physicians induce analgesia as soon as the diagnosis of active labor has been established and the patient has requested pain relief. The most common complications occurring with epidural analgesia are maternal hypotension and postdural puncture headache. Retrospective studies have demonstrated an association between epidural analgesia and increases in duration of labor, instrumental vaginal delivery and cesarean section for labor. However, several recent prospective studies have concluded that epidural analgesia does not adversely affect the progress of labor or increase the rate of cesarean section. These remain controversial issues among practicing physicians.
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Analgesia Epidural , Analgesia Obstétrica , Trabajo de Parto , Analgesia Epidural/efectos adversos , Analgesia Epidural/métodos , Analgesia Obstétrica/efectos adversos , Analgesia Obstétrica/métodos , Contraindicaciones , Femenino , Humanos , Selección de Paciente , Embarazo , Factores de TiempoRESUMEN
The DNA sequence and studies on the expression of the NUC1 gene from Saccharomyces cerevisiae are presented. The NUC1 locus is located in the distal portion of the left arm of Chromosome X and encodes the major nuclease found in mitochondria. The inferred amino acid sequence of NUC1 predicts that the nuclease is basic, rich in prolines, of average hydrophobicity, and has a molecular weight for the primary translation product of 37,209 daltons. NUC1 is very poorly expressed, consistent with the codon usage bias determined from the DNA sequence and our previous determination of the number of enzyme molecules per cell. Mapping of the 5' terminus of the NUC1 mRNA reveals that the mRNA has a long 400 base untranslated leader in which are found three open reading frames, each initiated by an AUG. The possibility that these upstream open reading frames contribute to the poor expression of the NUC1 gene is discussed.
Asunto(s)
Endonucleasas/genética , Proteínas Fúngicas/genética , Genes Fúngicos , Mitocondrias/enzimología , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Secuencia de Bases , Genes , Datos de Secuencia Molecular , Saccharomyces cerevisiae/enzimologíaRESUMEN
The nuclear gene from Saccharomyces cerevisiae that encodes the major mitochondrial nuclease was cloned. Gene sequences were identified from a lambda gt11 library by antibodies specific to the mitochondrial nuclease. DNA from the phage recombinant was used to isolate the entire nuclease gene from a plasmid library. Yeast strains containing the nuclease gene on a multicopy plasmid vector overproduced mitochondrial nuclease 20-40 times relative to a wild-type strain. Strains containing a null allele of the nuclease gene lacked all traces of mitochondrial nuclease. Both cell types, however, were phenotypically wild-type indicating that the nuclease is not an essential enzyme for mitochondrial function. The locus encoding the mitochondrial nuclease is termed NUC1.
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Endonucleasas/genética , Exonucleasas/genética , Genes Fúngicos , Mitocondrias/enzimología , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Genes , Proteínas Recombinantes de Fusión/genética , Saccharomyces cerevisiae/enzimologíaRESUMEN
Different molecular weight forms of the protein product of the yeast mitochondrial gene var 1 are shown at arise by a process of asymmetric gene conversion. These different forms can be accounted by two DNA segments, 36 and 57 base pairs long, present in one allelic form of the var 1 structural gene, which can be inserted independently and at different frequencies into other var 1 alleles.
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ADN Mitocondrial/genética , Recombinación Genética , Saccharomyces cerevisiae/genética , Alelos , Genes , Modelos Biológicos , Peso Molecular , Péptidos/genética , Polimorfismo Genético , ARN Ribosómico/genéticaRESUMEN
The var1 locus on yeast mitochondria) DNA is defined by a set of alleles that affect the apparent size (Mr 40,000-44,000) of a mitochondria) translation product (var1), a protein of the mitochondria) 38S ribosomal subunit. Using petite deletion and restriction endonuclease site mapping, we have defined the physical location of all var1 alleles to a specific restriction fragment of roughly 2.1 kbp located between the antibiotic resistance loci ery1 and olil. Surprisingly, from base sequence studies of this region by Tzagoloff et al. (1980), it appears that the DNA fragment we have mapped contains little or none of the structural gene for the var1 protein since the fragment is composed primarily of long stretches of dA + dT interspersed with short clusters high in dG + dC. Nevertheless, by a type of complementation test termed zygotic gene rescue (Strausberg and Butow, 1977), we show that with petites retaining that restriction fragment and short flanking sequences, var1 polypeptide characteristic of the strain from which the petite was derived, is expressed in zygotes formed between the petite and a wild-type tester. Thus the ability of the var1 determinant to act in trans suggests that control of expression of different var1 species involves intermolecular interactions, perhaps at the level of RNA splicing. Our results are discussed in terms of several possible models for the organization and control of the var1 structural gene.
RESUMEN
Twenty isolates of the dimorphic, pathogenic fungus Histoplasma capsulatum were divided into three classes based on comparisons of restriction enzyme digests of their mitochondrial DNA and rDNA. The majority of isolates, including most North American strains and the African H. capsulatum var. duboisii variants, belong to class 2. Isolates from Central America and South America make up class 3. The attenuated Downs strain is the only member of class 1.
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ADN de Hongos/análisis , Histoplasma/clasificación , África , Animales , América Central , Enzimas de Restricción del ADN , ADN de Hongos/genética , ADN Mitocondrial/análisis , Histoplasma/genética , Histoplasma/aislamiento & purificación , Humanos , América del Norte , Hibridación de Ácido Nucleico , ARN de Hongos/genética , ARN Ribosómico/genética , América del SurRESUMEN
Magnesium sulfate (MgSO4) attenuates the maternal compensatory response to hemorrhage in gravid ewes, perhaps by decreasing the response to endogenous vasopressors. The purpose of this study was to determine whether MgSO4 alters the cardiovascular response of gravid ewes to vasopressor agents. Sixteen gravid ewes underwent a series of experiments consisting of administration of two exogenous and two endogenous vasopressors, each with and without a concurrent MgSO4 infusion. Dose-response curves were constructed for phenylephrine (an alpha 1-adrenergic agonist), ST-91 (an alpha 2-adrenergic agonist), angiotensin II, and arginine vasopressin (AVP). MgSO4 significantly attenuated the increase in maternal mean arterial pressure and systemic vascular resistance and the decrease in cardiac output during ST-91 infusion but not during phenylephrine, angiotensin II, or AVP infusions. MgSO4 significantly attenuated the increase in uterine vascular resistance during phenylephrine, ST-91, and angiotensin II infusions and the decrease in uterine blood flow during phenylephrine and angiotensin II infusions. MgSO4 also appeared to attenuate the decrease in uterine blood flow during ST-91 infusion (P = 0.067). The present study suggests that MgSO4 antagonizes the effects of alpha 1-adrenergic agonists, alpha 2-adrenergic agonists, and angiotensin II on the uterine vasculature, thus providing a level of protection for the fetus in situations of maternal stress.
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Angiotensina II/farmacología , Arginina Vasopresina/farmacología , Clonidina/análogos & derivados , Sulfato de Magnesio/farmacología , Fenilefrina/farmacología , Útero/irrigación sanguínea , Resistencia Vascular/efectos de los fármacos , Animales , Clonidina/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Concentración de Iones de Hidrógeno , Embarazo , Flujo Sanguíneo Regional/efectos de los fármacos , OvinosRESUMEN
BACKGROUND: Some studies suggest that epidural analgesia prolongs labor and increases the incidence of cesarean section, especially if it is administered before 5 cm cervical dilation. The purpose of the current study was to determine whether early administration of epidural analgesia affects obstetric outcome in nulliparous women who are receiving intravenous oxytocin. METHODS: Informed consent was obtained from healthy nulliparous women with a singleton fetus in a vertex presentation, who requested epidural analgesia while receiving intravenous oxytocin at at least 36 weeks' gestation. Each patient was randomized to receive either early or late epidural analgesia. Randomization occurred only after the following conditions were met: (1) the patient requested pain relief at that moment, (2) a lumbar epidural catheter had been placed, and (3) the cervix was at least 3 but less than 5 cm dilated. Patients in the early group immediately received epidural bupivacaine analgesia. Patients in the late group received 10 mg nalbuphine intravenously. Late-group patients did not receive epidural analgesia until they achieved a cervical dilation of at least 5 cm or until at least 1 h had elapsed after a second dose of nalbuphine. RESULTS: Early administration of epidural analgesia did not prolong the interval between randomization and the diagnosis of complete cervical dilation, and it did not increase the incidence of malposition of the vertex at delivery. Also, early administration of epidural analgesia did not result in an increased incidence of cesarean section or instrumental vaginal delivery. Thirteen (18%) of 74 women in the early group and 14 (19%) of 75 women in the late group underwent cesarean section (relative risk for the early group 0.94; 95% confidence interval 0.48-1.84). Patients in the early group had lower pain scores between 30 and 120 min after randomization, and were more likely to experience transient hypotension. Infants in the late group had lower umbilical arterial and venous blood pH and higher umbilical arterial and venous blood carbon dioxide tension measurements at delivery. CONCLUSIONS: Early administration of epidural analgesia did not prolong labor or increase the incidence of operative delivery, when compared with intravenous nalbuphine followed by late administration of epidural analgesia, in nulliparous women who were receiving intravenous oxytocin.
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Analgesia Epidural/efectos adversos , Analgesia Obstétrica/efectos adversos , Cesárea/estadística & datos numéricos , Oxitocina/efectos adversos , Adulto , Bupivacaína/administración & dosificación , Esquema de Medicación , Femenino , Humanos , Inyecciones Intravenosas , Trabajo de Parto/efectos de los fármacos , Oxitocina/administración & dosificación , Dimensión del Dolor , Paridad , EmbarazoRESUMEN
Earlier studies have suggested that epidural fentanyl improves intraoperative analgesia during cesarean section, but others have suggested that it worsens postoperative analgesia from epidural morphine. The purpose of this study was to determine whether epidural fentanyl given before epidural morphine improves the quality of intraoperative epidural anesthesia without worsening postoperative analgesia provided by epidural morphine. Sixty patients having epidural anesthesia for cesarean delivery were studied. Epidural anesthesia was established using 2% lidocaine with epinephrine 5 micrograms/mL. After delivery, either fentanyl 100 micrograms/10 mL or normal saline-control 10 mL was injected through the epidural catheter in a randomized, double-blind manner. All patients received 3.5 mg of morphine epidurally after uterine repair. After administration of the epidural study drug, there were no significant differences in the pain responses during surgery between the two groups. Patients in the fentanyl group experienced significantly less nausea and vomiting between delivery and the end of surgery than did patients in the normal saline-control group (P = 0.013). Postoperatively, visual analogue scale scores for pain, pruritus, nausea, and sedation were similar at 1, 2, 4, and 8 h in the two groups. We conclude that fentanyl 100 micrograms administered epidurally during cesarean delivery did not improve intraoperative analgesia, but significantly reduced intraoperative nausea and vomiting without diminishing the efficacy of postoperative analgesia provided by epidural morphine.
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Anestesia Obstétrica , Cesárea , Fentanilo/efectos adversos , Morfina/antagonistas & inhibidores , Dolor Postoperatorio/tratamiento farmacológico , Adulto , Femenino , Fentanilo/administración & dosificación , Humanos , Inyecciones Epidurales , Periodo Intraoperatorio , Morfina/uso terapéutico , Náusea/inducido químicamente , Dimensión del Dolor , Embarazo , Prurito/inducido químicamenteRESUMEN
Magnesium sulfate worsens maternal hypotension and fetal oxygenation during hemorrhage in gravid ewes. The purpose of this study was to determine whether calcium chloride administration is a useful adjunct to blood transfusion during hemorrhagic hypotension in hypermagnesemic gravid ewes. Sixteen experiments were performed in eight chronically instrumented animals between 0.8 and 0.9 of timed gestation. The experimental sequence included (a) T = 0: magnesium sulfate 4 g IV; (b) T = 5: infusion of magnesium sulfate 4 g/h IV; (c) T = 90: maternal hemorrhage 20 mL/kg over 55 min; (d) T = 147: calcium chloride 10 mg/kg or normal saline (NS-control) 0.1 mL/kg IV; (e) T = 160: transfusion of collected maternal blood over 55 min. Magnesium sulfate alone slightly decreased maternal mean arterial pressure (P = 0.002) and increased uterine blood flow (P = 0.0001) in both groups before hemorrhage. During hemorrhage, maternal mean arterial pressure, cardiac output, and uterine blood flow, and fetal PO2 and pH all decreased sharply (P = 0.0001). Cardiac output increased (P = 0.0005) modestly just after the intravenous bolus of calcium chloride. Maternal mean arterial pressure was significantly higher (P = 0.03) during transfusion in the calcium chloride group than in the NS-control group, but only after mean arterial pressure was near baseline measurements. Maternal uterine blood flow and fetal PO2 and pH responses over time were similar in the two groups. We conclude that intravenous administration of calcium chloride (10 mg/kg) transiently increased cardiac output during hemorrhagic hypotension and slightly increased mean arterial pressure during transfusion in hypermagnesemic gravid ewes.(ABSTRACT TRUNCATED AT 250 WORDS)
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Cloruro de Calcio/uso terapéutico , Hemodinámica/efectos de los fármacos , Hemorragia/complicaciones , Hipotensión/tratamiento farmacológico , Sulfato de Magnesio/toxicidad , Útero/irrigación sanguínea , Animales , Cloruro de Calcio/sangre , Femenino , Feto/efectos de los fármacos , Frecuencia Cardíaca Fetal/efectos de los fármacos , Hipotensión/etiología , Sulfato de Magnesio/sangre , Embarazo , OvinosRESUMEN
Recent studies suggest that epidural anesthesia initiated before hemorrhage may improve survival and acid-base status in laboratory animals. However, studies of hemorrhagic shock in nonpregnant animals may not be applicable to less severe hemorrhage in pregnant animals. The purpose of this study was to determine whether epidural anesthesia alters maternal and fetal hemodynamic and acid-base responses to hemorrhage in gravid ewes. Twenty-four experiments were performed in twelve chronically instrumented animals between 0.8 and 0.9 of timed gestation. The experimental sequence included: 1) T = 0 min: normal saline 500 ml intravenously; 2) T = 15 min: epidural administration of 0.5% bupivacaine (epidural group) or normal saline (control group); 3) T = 30 min: epidural administration of additional 0.5% bupivacaine (epidural group only) if the sensory level of anesthesia was below T10; 4) T = 45 min: maternal hemorrhage 20 ml/kg over 55 min; and 5) T = 110 min: transfusion of collected maternal blood over 55 min. At 45 min (i.e., 30 min after the epidural injection of bupivacaine), epidural bupivacaine resulted in a median sensory level of T9 in the epidural group. At that time, maternal mean arterial pressure was less (P less than 0.05) in the epidural group than in the control group (14 +/- 2% below baseline versus 4 +/- 1% above baseline, respectively). Maternal mean arterial pressure, heart rate, cardiac output, and uterine blood flow, and fetal PO2 and pH all were significantly less during hemorrhage (P less than 0.05) in the epidural group than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anestesia Epidural , Anestesia Obstétrica , Bupivacaína/efectos adversos , Feto/metabolismo , Lidocaína/efectos adversos , Choque Hemorrágico/metabolismo , Útero/irrigación sanguínea , Animales , Dióxido de Carbono/sangre , Epinefrina/sangre , Femenino , Feto/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Concentración de Iones de Hidrógeno , Oxígeno/metabolismo , Embarazo , Ovinos , Hemorragia Uterina/metabolismoRESUMEN
Ephedrine restores and/or protects uterine blood flow and fetal well-being in laboratory animals. In contrast, alpha 1-adrenergic agonists worsen uterine blood flow and fetal condition. We previously demonstrated that magnesium sulfate (MgSO4) attenuates the detrimental effects of phenylephrine on uterine vascular resistance in gravid ewes. Therefore, we performed this study to determine whether ephedrine or phenylephrine better restores and protects uterine blood flow and fetal oxygenation during epidural anesthesia-induced hypotension in hypermagnesemic gravid ewes. Twelve chronically instrumented gravid ewes were each used for three experiments: 1) ephedrine, 2) phenylephrine, and 3) normal saline (NS)-control. For each experiment the protocol was as follows: 1) at time zero, intravenous infusion of MgSO4 was begun; 2) at 150 min a thoracic level of epidural anesthesia was achieved with 2% lidocaine; and 3) at 165 min, an intravenous infusion of ephedrine, phenylephrine, or NS was begun and continued through 195 min. Epidural anesthesia uniformly decreased maternal mean arterial blood pressure (MAP), heart rate, cardiac output, uterine blood flow, and fetal PO2 in each of the three groups. Both ephedrine and phenylephrine restored maternal MAP to baseline, as expected from the experimental design. Ephedrine significantly increased cardiac output and uterine blood flow when compared with NS-control, but phenylephrine did not. Phenylephrine significantly increased uterine vascular resistance when compared with NS-control, but ephedrine did not. As a result, fetal pH and PO2 were significantly greater during ephedrine infusion than during infusion of NS-control. Fetal pH was stable during ephedrine infusion, but it continued to decrease during phenylephrine infusion.(ABSTRACT TRUNCATED AT 250 WORDS)